Overhead door systems, particularly electrically operated overhead doors such as for example, residential electric garage door openers (GDOs) have been in use for over 30 years and it is estimated that there are over 30 million electric garage door openers operating in the United States today. Many of these GDOs are equipped with object sensor devices that are designed to stop a garage door from accidentally closing if it encounters any blockage, such as a child, motor vehicle or other object in its path. These object sensor devices are primarily designed as safety devices and are required by law on all GDOs manufactured for use in the United States today. A typical object sensor device as shown in U.S. Pat. No. 4,922,168 (Waggamon et al) is usually paired together as an infrared light beam transmitter and infrared receiver. These units are normally mounted opposite one another on the bottom of each side of the garage door's track and about six inches from the ground. If the beam is broken or interrupted while the garage door is closing or moving down, the GDO will either stop or reverse direction back to the up or open position. Another object sensor device is disclosed in U.S. Pat. No. 6,176,039 (Craig) and is physically mounted on the garage door to sense objects as it travels along with the leading edge of the garage door. Both devices adequately detect objects in proximity to the bottom of the garage door near the end of travel. These devices however cannot detect objects that are in the garage door travel path.
Sport utility vehicles (SUV's), vans and minivans have become very popular particularly for families because they have a larger people and large carrying capacity and therefore are being purchased in increasing numbers for both personal and business use. SUV's, vans, minivans, station wagons and similar vehicles typically have large hatchbacks. When fully or partially opened in a garage, the hatchback sometimes extends into the travel path of many residential garage doors due to inadequate ceiling heights to provide sufficient clearance. In some cases, the hatchback is directly in-line with the overhead door hanging arm which may protrude up to seven inches below the garage door in its open position, and in worst cases, the hatchback may actually touch the open garage door. This condition creates a potential problem especially if someone accidentally operates the electric GDO to open or close the overhead door when the hatch is open. In such instances, the GDO's door hanging arm and/or the garage door's center hinges and door lock scratches or scrapes its way along the surface of the vehicle's open hatch creating substantial damage to the surface paint and finish. In extreme cases, the GDO's door hanging arm can tear away the vehicle's rear windshield wiper on the hatchback or rip off trim causing hundreds of dollars of damage. The above-mentioned infrared devices are not capable in preventing this type of damage to a vehicle's hatchback.
Prior art garage door object sensor systems typically use complicated infrared transmitters and receivers that can be difficult to set-up and maintain and are easily knocked out of alignment making the garage door inoperative without any interfering object being present in the garage door travel path.
A further shortcoming of prior art garage door object sensor systems is objects can only be sensed in the travel path in the forward travel entry closing direction and not in the reverse travel path entry opening direction.
Accordingly there is a need for an overhead door object sensor system that can sense an object when moving in both a forward travel path to an entry closing position and a reverse travel path to an entry open position to immobilize door movement when a hatch portion of a vehicle is in its open position orientation.
It is an object of the present invention therefore to provide an overhead door sensor system to immobilize door movement when the hatch portion of a vehicle is in its open position orientation.
It is a further object of the present invention to provide an overhead door immobilizer that can be used with overhead door electric power opener systems.